Electrophoretic properties of temperature-sensitive mutant particles of simian virus 40

Forty-five temperature-sensitive strains of simian virus 40 (SV40) particles belonging to four complementation groups were analyzed by agarose gel electrophoresis. Five strains (B204, B218, B233, and BC226), which are members of the B and BC complementation groups, yielded virions with aberrant mobilities. Genetic mapping by LAI and NATHANS suggested that B and BC mutantions are in a single gene. The mutant virions possessing altered mobilities have greater positive charges than wild-type particles. The findings presented here indicate that the product of gene B and BC is a significant component of the SV40 capsid.